Search results for "HOLOCENE"
showing 10 items of 330 documents
Palaeogeographical evolution of the Egadi Islands (western Sicily, Italy). Implications for late Pleistocene and early Holocene sea crossings by huma…
2019
Abstract The continental shelf morphology offshore of western Sicily suggests that during the Last Glacial Maximum (LGM, 20 ka cal BP), two of the Egadi Islands, Favignana and Levanzo, were connected to Sicily by a wide emerged plain, while Marettimo was only separated from the other islands by a narrow channel. We studied the relative sea-level variation from the LGM until today, focussing on two important time slices: the Mesolithic (9.5–13 ka cal BP) and the Neolithic (6.5–7.5 ka cal BP). In this research, we discuss a sea-level rise model by means of geomorphological, archaeological and geophysical observations and new radiocarbon dating of marine and terrestrial fossil fauna. The resul…
Human settlements in the Mediterranean and the sea level changes from 12 ka to the present
2012
Understanding past sea-level change plays an important role in determining the underlying causes, and also allows the extrapolation of past sea levels to locations and epochs for which there are no instrumental data. A compilation of global sea-level estimates based on deep-sea oxygen isotope ratios at millennial-scale resolution or higher was published since ‘70. These global sea level curves do not take in account isostasy and tectonics. Observed sea level change can be reconstructed from dated fossils, coral reef terraces, speleothems, emerged and forming terraces on coastal areas, archaeological and other markers well connected with sea level. Because of the lack of coral reefs in the M…
Abrupt vegetation changes in the Segura Mountains of southern Spain throughout the Holocene
2001
Summary 1 The fossil pollen record of Canada de la Cruz in the Segura mountains of southern Spain yields insights into high-elevation vegetational dynamics over the last c. 8320 years. Phases of xerophytic grassland alternate with high-mountain open pine forests and expansion of deciduous forests and Mediterranean scrub at lower altitudes. 2 Longer-term stable vegetation patterns are interrupted by multidecadal to century-scale shifts at about 7770, 3370, 2630, 1525 and 790 years BP. 3 Some of the vegetation types have no modern analogues and represent high-altitude remnants of widespread last-glacial xerophytic communities. Other species patterns, characteristic of current scrub associatio…
Environmental changes during the Upper Pleistocene–Holocene in Mediterranean NE Spain as recorded by the mineralogy and geochemistry of alluvial reco…
2013
Abstract Landscape evolution and environmental conditions from Last Glacial Maximum (LGM) to Late Holocene times were reconstructed from the mineralogical and geochemical characteristics of the alluvial morphochronostratigraphy, recorded in Bardenas Reales Natural Park (Ebro Basin, NE Spain). Alluvial architecture includes a LGM-Holocene gravelly unit (≈22–9 ka BP), a Lower Holocene silty–muddy unit (≈9–7 ka BP), and an Upper Holocene sandy unit (≈5–0.1 ka BP). Increases in illite–smectite mixed layers, kaolinite, chlorite and modified Chemical Index of Alteration (CIA*), as well as the decrease in illite FWHM(E), are indicators of minor increases in the chemical weathering of the alluvial …
Holocene paleoclimate inferred from salinity histories of adjacent lakes in southwestern Sicily (Italy)
2016
Marked uncertainties persist regarding the climatic evolution of the Mediterranean region during the Holocene. For instance, whether moisture availability gradually decreased, remained relatively constant, or increased during the last 7000 years remains a matter of debate. To assess Holocene limnology, hydrology and moisture dynamics, the coastal lakes Lago Preola and Gorgo Basso, located in southwestern Sicily, were investigated through several stratigraphic analyses of ostracodes, including multivariate analyses of assemblages, transfer functions of salinity, and biochemical analyses of valves (Sr/Ca, δ18O and δ13C). During the early Holocene, the Gorgo Basso and Lago Preola ostracode rec…
Biochronological and paleoenvironmental interest of foraminifera lived in restricted environments: application to the study of the western Mediterran…
2002
As a consequence ofthe Flandrian transgression, numerous littoral lakes were f since roughly 6000 BP in the western Mediterranean coast. This kind of environment is colonized, among other groups, by specialized forms of foraminifera. Some species arose in the Upper Tertiary, some others in the Pleistocene and others are exclusively Holocene. Two kinds ofenvironment are proposed in the colonization: one with very low salinity waters where agglutinated test species prevail and another one with brackish waters, dominated by calcareous test species. In addition, Trichohyalus aguayoi can be considered as an acmezone within the Holocene. We propose a cenozone formed by the following assemblage: A…
The influence of climate and sea-level change on the Holocene evolution of a Mediterranean coastal lagoon: Evidence from ostracod palaeoecology and g…
2013
Abstract Coastal lagoons provide an excellent basis for the study of processes controlling the evolution of a coastal zone. We examine the relative importance of these processes during the middle to late Holocene through a study of an 8.5 meter-long sediment record from the Albufera de Valencia (Spain). We combine sedimentological analyses with investigations into the palaeoecology, taphonomy and geochemistry (Mg/Ca, Sr/Ca, δ 18 O and δ 13 C) of ostracod valves in order to assess the effects of sea-level changes, storm events and effective moisture on the evolution of a Western Mediterranean coastal wetland. The late Pleistocene sediments represent a subaerial environment, which was followe…
Benthic foraminifera and environmental changes in the Quaternary of the western Mediterranean coast: the core of Xeraco, Valencia, Spain
2020
The evolution of the benthic foraminiferal assemblages from a 60 m core drilled in the Quaternary lagoon of Xeraco (Valencia, Spain) is studied. Two moments of warm climate, high sea-level and maximal marine influence in the lagoon have been identified. The first one at the base of the core, punctuated by highly frequent changes during the Upper Pleistocene, and the other one in the upper end of the series during the Holocene. The presence of a middle core section with low diversity and a nearly total absence of marine foraminifers is interpreted as a regressive interval of cold climate conditions linked to a glacial stage.
A high-resolution record of the last deglaciation in the Sicily Channel based on foraminifera and calcareous nannofossil quantitative distribution
2003
Abstract Relative abundance fluctuations in planktic foraminiferal and calcareous nannofossil assemblages are reported on the basis of a high-resolution study of ODP Leg 160 Hole 963D, drilled in the Sicily Strait, near Capo Rossello (southern Sicily). With its 8 m of undisturbed sediments, the core covers the interval from 1.5 to 23 kyr, allowing a 50–100-yr sampling resolution. All the short warm and cold events and sub-events recorded in this time interval in the GRIP Greenland ice core and at several Mediterranean sites were recognized. On this basis, a total number of nine ecozones based on planktic foraminifera and seven ecozones based on calcareous nannofossils were identified. A sho…
Surviving the Holocene: Human Ecological Responses to the Current Interglacial in Southern Valencia, Spain
2009
For hunter-gatherer groups, the dramatic changes in climate at the end of the last glacial cycle necessitated rearrangement of land use, including shifts in mobility strategies, settlement location, and resource use. We examine these behavioral changes using lithic attribute data as well as spatial distributions of artifacts and features. Using data from intensive survey and excavation, we trace human ecological response through the onset of the current interglacial in central Mediterranean Spain, comparatively far from the margins of the north-temperate ice sheets.